In a time division multiplexing (Time Division Multiplexing, TDM) network, the network tracks user calls to determine switches that the user calls pass. In the TDM network, voice information is transmitted in pulse-code modulation (Pulse-code modulation, PCM) stream mode after being encoded and decoded. Service personnel determine a loopback node of a user call, log in to a platform of a switch serving as the loopback node, search for a time slot used by the call at the switch, and then set that PCM streams received at the time slot from a gateway are directly output through a local loopback. That is, the PCM streams are output through an input port where the PCM streams are received. In this way, the PCM streams sent from the gateway are directly sent back to the gateway after being transmitted to the loopback node, thereby achieving voice loopback.
The disadvantage of the existing technology is as follows:
A voice loopback technology in the TDM network is provided in the prior art, but in the VoIP network, no voice loopback solution is provided.